Remove MSC library, it is not used anywhere

ci-scripts/yaml_files/fr1_epc_20897/mme.conf

ci-scripts/yaml_files/magma_nsa_20897/mme.conf

cmake_targets/CMakeLists.txt

cmake_targets/at_commands/CMakeLists.txt

cmake_targets/build_oai

cmake_targets/epc_test/CMakeLists.template

cmake_targets/install_external_packages.ubuntu20

cmake_targets/s1c_mme_test/CMakeLists.template

cmake_targets/tools/build_helper

cmake_targets/tools/example_enb_exmimo_mme_hss.txt

cmake_targets/tools/example_oaisim_enb_ue_mme_virtual.txt

cmake_targets/tools/run_enb_s1_usrp

cmake_targets/tools/run_enb_ue_virt_noS1

cmake_targets/tools/run_enb_ue_virt_s1

common/config/DOC/config/rtusage.md

common/utils/LOG/DOC/rtusage.md

common/utils/LOG/log.c

common/utils/LOG/log.h

common/utils/msc/msc.c

common/utils/msc/msc.h